اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدDark Matter Particle Spectroscopy at the LHC: Generalizing MT2 to Asymmetric Event Topologies
123
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We consider SUSY-like missing energy events at hadron colliders and critically examine the common assumption that the missing energy is the result of two identical missing particles. In order to experimentally test this hypothesis, we generalize the subsystem MT2 variable to the case of asymmetric event topologies, where the two SUSY decay chains terminate in different children particles. In this more general approach, the endpoint MT2max of the MT2 distribution now gives the mass Mp(Mc(a),Mc(b)) of the parent particle as a function of two input children masses Mc(a) and Mc(b). We propose two methods for an independent determination of the individual children masses Mc(a) and Mc(b). First, in the presence of upstream transverse momentum P(UTM) the corresponding function Mp(Mc(a),Mc(b),P(UTM)) is independent of P(UTM) at precisely the right values of the children masses. Second, the previously discussed MT2 kink is now generalized to a ridge on the 2-dimensional surface Mp(Mc(a),Mc(b)). As we show in several examples, quite often there is a special point along that ridge which marks the true values of the children masses. Our results allow collider experiments to probe a multi-component dark matter sector directly and without any theoretical prejudice.
قيم البحث
اقرأ أيضاً
We propose a novel method for probing sleptons in compressed spectra at hadron colliders. The process under study is slepton pair production in R-parity conserving supersymmetry, where the slepton decays to a neutralino LSP of mass close to the slept
on mass. In order to pass the trigger and obtain large missing energy, an energetic mono-jet is required. Both leptons need to be detected in order to suppress large standard model backgrounds with one charged lepton. We study variables that can be used to distinguish the signal from the remaining major backgrounds, which include tt, WW+jet, Z+jet, and single top production. We find that the dilepton MT2, bound by the mass difference, can be used as an upper bound to efficiently reduce the backgrounds. It is estimated that sleptons with masses up to about 150 GeV can be discovered at the 14 TeV LHC with 100/fb integrated luminosity.
We investigate the current status of the light neutralino dark matter scenario within the minimal supersymmetric standard model (MSSM) taking into account latest results from the LHC. A discussion of the relevant constraints, in particular from the d
ark matter relic abundance, leads us to a manageable simplified model defined by a subset of MSSM parameters. Within this simplified model we reinterpret a recent search for electroweak supersymmetric particle production based on a signature including multi-taus plus missing transverse momentum performed by the ATLAS collaboration. In this way we derive stringent constraints on the light neutralino parameter space. In combination with further experimental information from the LHC, such as dark matter searches in the monojet channel and constraints on invisible Higgs decays, we obtain a lower bound on the lightest neutralino mass of about 24 GeV. This limit is stronger than any current limit set by underground direct dark matter searches or indirect detection experiments. With a mild improvement of the sensitivity of the multi-tau search, light neutralino dark matter can be fully tested up to about 30 GeV.
Effective field theory (EFT) formulations of dark matter interactions have proven to be a convenient and popular way to quantify LHC bounds on dark matter. However, some of the non-renormalizable EFT operators considered do not respect the gauge symm
etries of the Standard Model. We carefully discuss under what circumstances such operators can arise, and outline potential issues in their interpretation and application.
We study the collider phenomenology of dark matter pair production at the LHC in simplified dark matter models and in the MSSM. Among the large space of dark matter models, we focus on two particular models where a fermionic dark matter candidate int
eracts with the Standard Model via the exchange of either a vector mediator in the s-channel or coloured scalar mediators in the t-channel. We find that the simplified models are capable of reproducing the predictions of the MSSM to some extent in simplified supersymmetric scenarios, but lack the complexity to descibe the complete theory over the full supersymmetric parameter space.
The vector boson fusion (VBF) event topology at the Large Hadron Collider (LHC) allows efficient suppression of dijet backgrounds and is therefore a promising target for new physics searches. We consider dark matter models which interact with the Sta
ndard Model through the electroweak sector: either through new scalar and pseudoscalar mediators which can be embedded into the Higgs sector, or via effective operators suppressed by some higher scale, and therefore have significant VBF production cross-sections. Using realistic simulations of the ATLAS and CMS analysis chain, including estimates of major error sources, we project the discovery and exclusion potential of the LHC for these models over the next decade.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
